This disclosure relates in general to securing controlled areas and, but not by way of limitation, to automatic security systems used for controlled areas.
There are terrorism concerns in many contexts. Situations where people congregate have become attractive targets for those who plant bombs. Terrorists often rely upon forged authentication documents such that knowing true identities is not possible. Additionally, terrorists seek out situations where they can anonymously gain access to large amounts of people to increase the impact of their bombs.
Airports have a long history of controlling access by persons with certain items that could aid hijacking an airplane. For example, airports have security checkpoints where metal detectors are used on people and carry-on bags are searched. Some airports use X-ray machines on bags and chemical detectors on bags and people. These systems interrogate a bag or person without knowing the identity of the person being interrogated.
Security systems are used to secure areas. Things such as security codes, biometric information and/or identity cards are used to authenticate a person before authorizing entry to the secure area. In these circumstances, a known person is authenticated by way of the information provided. For example, a new person is added to the database of allowed persons along with the code from their identity card. When the identity card is provided, the person is allowed entry to the secured area.
Transit systems have been the subject of terrorist incidents. Suicide bombers have carried bombs into buses or trains. Additionally, bombs have been left in public transport by terrorists. Increased foot patrols have been used for transit systems to increase the likelihood of apprehending terrorists or bombs they have left behind. In some cases, canine officers are used to try to find those carrying explosives or the explosives themselves.